What is the Dataviewer Telling Me? Round 2

[duster360]

Really? where are you getting your information?

You're going to have to expand your knowlege base from a single year and model of vehical.

[Quick]

LT adaptives don't update until ECT is Over 176F. So if your statment were true, ANY and ALL LT adaptive would remain 0% until this ECT temp is reached. This is not the case.

During CLOSED LOOP modes the PCM monitors the inputs from the upstream and downstream heated oxygen sensors. The upstream heated oxygen sensor input tells the PCM if the calculated injector pulse width resulted in the ideal air-fuel ratio of 14.7 to one. By monitoring the exhaust oxygen content through the upstream heated oxygen sensor, the PCM can fine tune injector pulse width. Fine tuning injector pulse width allows the PCM to achieve optimum fuel economy combined with low emissions.

For the PCM to enter CLOSED LOOP operation, the following must occur:
1. Engine coolant temperature must be over 35°F.
• If the coolant is over 35°F the PCM will wait 38 seconds.
• If the coolant is over 50°F the PCM will wait 15 seconds.
• If the coolant is over 167°F the PCM will wait 3 seconds.
2. For other temperatures the PCM will interpolate the correct waiting time.
...

When you turn the key it's in Startup Mode (Open Loop) and takes the atmospheric pressure. In 1 revolution it determines the crank position. After determining crank position it starts energizing the injectors in sequence. Once it's at +/-64 RPM of target it determines the injector pulse width based on MAP, Engine RPM, Battery voltage, Engine coolant temperature, Inlet/Intake air temperature (IAT), Throttle position, The number of engine revolutions since cranking was initiated. Timing is at 9* BTDC.

That's why you get that wonderful "bark" when you fire it.

Then it goes into Warmup Mode (Open Loop) and then to Cruise or Idle Mode as above which is Closed Loop and it's monitoring the 02 sensors and adjusting Lt adaptives.

[duster360]

LT adaptives don't update until ECT is Over 176F. So if your statment were true, ANY and ALL LT adaptive would remain 0% until this ECT temp is reached. This is not the case.

Reread my post 2-3 more times.

I didn't say anything about the temp the PCM enters Closed loop. I was clearly referring to the engine temp that LT adaptives are allowed to be updated by ST.

I can copy/paste service manuals too.

The values stored in long term adaptive memory are used for all operating conditions, including open loop and cold starting. However, the updating of the long term memory occurs after the engine has exceeded approximately 170°-190° F, with fuel control in closed loop and two minutes of engine run time. This is done to prevent any transitional temperature or start-up compensations from corrupting long term fuel correction.

Closed loop Long Term Adaptive Memory is maintained above 170° to 190° F unless the PCM senses wide open throttle.